1. Field of the Invention
The present invention relates to an electric connector, and more particularly to an electric connector having a lock device.
2. Description of the Related Art
An expansion card is a common device of a circuit board, and an electronic component having a corresponding function can be produced on the circuit board by electrically connecting the corresponding circuits of a connector and a motherboard. In general, it requires a locking device to secure the connection of an expansion card with a connector. U.S. Pat. No. 5,494,451 discloses a structure of a retaining latch of a printed circuit board for securing a connector that is plugged into the printed circuit board. The aforementioned retaining latch comprises a connector fastening portion for engaging a connector and a board fastening portion for engaging the edge of the printed circuit board, and the connector fastening portion and the board fastening portion are connected by a resilient portion. Further, the board fastening portion includes a release tab connected to the board fastening portion for separating the printed circuit board from the board fastening portion. However, the foregoing structure requires repeated bending in the latching process, and thus causing a permanent deformation to the retaining latch easily. Furthermore, the holding force of such retaining latch is very small, and the retaining latch will be loosened easily, and thus causing a poor contact with the expansion card and affecting the normal electric connection. Therefore, it is necessary to design a novel electric connector to overcome the foregoing shortcomings.